Improvement in the manufacture of paper-pulp



AYMLZASM. F. W. ZANDERS.

Improvement in the Manufacture of Paper Pulp.

No.123,757 Patented Feb. 13, 1372.

l r flfiwazflizw.

F. W. ZANDERS.

Improvement in the Manufacture of Paper Pulp.-

No.l23, 75 7. I Patented Feb. 13,1872.

Fig. 8.

UNITED STATES PATENT OFFICE.

FREDERICK W. ZANDERS, OF ERFURT, GERMANSL ASSIGNOR TO HIMSELF AND JULIUS H. TIEMANN, OF NEW YORK CITY.

IMPROVEMENT IN THE MANUFACTURE OF PAPER-PULP.

Specification forming part of Letters Patent No. 123,757, dated February 13, 1872.

SPECIFICATION.

. To all whom it may concern:

Be it known that I, FREDERICK WILLIAM ZANDERS, of Erfurt, in the Empire of Germany, (but who have declared my intention of becomin g a citizen of the United States,) have in vented a new and useful Improvement in the Manufacture of Paper-Pulp; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawing making part of this specification.

My invention relates to the process of pulping the paper-stock; and consists in subjecting the same to the action of a weak solution of caustic alkali previous to the operation of boiling, which latter is thereby more quickly and cheaply eflected. and in the arrangement of lyevat, steeping-chests, and boilers.

Figure 1 represents a longitudinal section of a building, showing the arrangement of the vat, chests, and boilers. Fig. 2 is a transverse section of the same.

The building represented has three stories. In the upper story is placed a tank, 0, for containing a weak alkaline solution, said tank being provided with faucets c c at either end directly above openings in the steeping-chests A A in the story below. These chests are hung upon horizontal axes, upon which they may revolve, and each is provided with two opposite openings covered by suitable heads a a, closing water-tight. In the lower story, beneath the steeping-chests, are two cylindrical boilers, B B, hung upon journals b b b b so as to revolve end over end. The axles, are hollow, and connected through stuffing-boxes with pipes, whereby steam or water is conducted to the boilers for boiling or washing the stock. Faucets d d are inserted in the lower ends for drawing off the liquid, the heads being removed when the contents are taken out. The engine-room is supposed to be at E. Proper arrangements of shafts, belts, and pulleys are made, whereby the boilers B B are revolved, and the other machinery of the mill put in operation.

The process is as follows: The straw, esparto grass, bamboo, or other fibrous material to be reduced to pulp, in proper condition, is placed in the steeping-chests A A, where it is covered with a weak solution of caustic alkali drawn from the tank (J, and allowed to steep without heat from three to six hours, more or less. This steeping partially separates the fibers, and greatly assists the boiling process. It is then emptied into the boilers B B in a stronger alkaline solution, and boiled until it becomes thoroughly disintegrated and freed from silica. The liquid is then drawn off, and

may be used for steeping a quantity of fresh material. The boiled stock 'or pulp is then washed in clear water, admitted to the boilers through the axles, after which the heads are removed and the pulp discharged into cars or barrows which are run under the boilers. It is then treated by bleaching, 8210., in the ordinary manner.

I claim as my invention 1. The process of steeping the paper-stock in a weak solution of caustic alkali of the ordinary temperature previous to the operation of boiling, substantially as set forth.

2. The arrangement of the lye-tank O, steep ing chest or chests A, and boiler or boilers B, substantially as described.

Flt. WM. ZANDERS.

Witnesses:

A. F. PIGKENS, E. L. TIEMANN. 

